In this work we present the numerical analysis of fully complex fields employing computer generated holograms,
implemented with a commercial amplitude liquid-crystal spatial light modulator (SLM). The hologram transmittance is
obtained by adding an appropriate bias function to the real cosine computer hologram of the encoded signal. For the
purpose of this work, we consider an appropriated bias function for a modulator in which the amplitude transmittance is
coupled with a phase modulation. This type of coupled phase appears in a commercial Twisted Nematic Liquid Crystal
Display (TNLCD), configured to provide amplitude modulation, with only two polarizers as external components. This
modulation curve was experimentally obtained and adjusted to a mathematical function. The numerical evaluation is
done by calculating the signal to noise ratio of the reconstructed complex fields for the real modulation curve. Results
show that for a good behavior for complex fields a constant bias function should be implemented. As a particular
interesting case we generate propagation invariant complex beams with high accuracy and simplicity.

In this work we present the experimental synthesis of fully complex fields employing computer generated holograms,
implemented with an amplitude liquid-crystal spatial light modulator (SLM). The hologram transmittance is obtained by
adding an appropriate bias function to the real cosine computer hologram of the encoded signal. The effect of finite pixel
size in the SLM is compensated by digital pre-filtering of the encoded complex signal. For the purpose of this work, we
consider an appropriated bias function for a modulator in which the amplitude transmittance is coupled with a linear
phase modulator. This type of coupled phase appears in a commercial Twisted Nematic Liquid Crystal Display
(TNLCD), configured to provide amplitude modulation, with only two polarizers as external components. We employ a
commercial TNLCD to generate experimentally Laguerre-Gauss beams and non-diffracting Bessel beams of several
orders.

We present a non-contact system for obtaining three-dimensional objects topography. The described system combines the fringe projection technique and the Talbot effect which is knowed like Talbot interferometry. In fringe projection technique, the digitalization is realized when black and white lines are projected over the object and this image is captured by the CCD. In Talbot interferometry, the object is collocated on one of the grating auto-image planes. The deformed grating image is captured by the CCD and superposed with other reference one that can be physical or computer generated (virtual/synthetic) for obtaining a moire pattern which gives information about the object topography. The topography of a coin and phalangeal articulation are obtained by using of this technique. The Spatial Synchronous Detection and Fourier Method were incorporate to retrieve the phase.

An image processing algorithm, mainly based on morphological enhancement and segmentation, is developed and applied to optical microscope images of transverse cuts of fabric filaments, to retrieve useful shape characteristics. Adaptive filtering and non-linear fitting algorithms are also applied. Computer generated noisy images are used to estimate the algorithm accuracy with excellent results. This algorithm is a significant improvement over the current human-based inspection method for filament shape analysis, and its development and application will improve quality control in textile industry. The complete procedure is outlined in the present work, showing relevant results and pointing out pertinent restrictions.

We propose and implement simplifications to the optimum configuration of a twisted-nematic liquid-crystal display (TNLCD) operating as a phase modulator. As previously proposed, such an optimum configuration requires a generator of elliptic polarization, at the input, and a detector of elliptic polarization, at the output. Both the generator and the detector of elliptic polarization are formed by a quarter wave plate and a linear polarizer, appropriately arranged.
As a first modification of the optimum phase configuration we removed the quarter-wave plate at the output of the TNLCD. The remaining components, two polarizers and a wave plate are arranged and oriented in such a way that the quality of phase modulation is very similar to that obtained with the arrange using two wave plates. This modification reduces complexity and cost of the mostly-phase setup arranged with the TNLCD. Our experimental implementation of the modified phase configuration employed a laser with a wavelength of 457 nm. As another modification of the setup, instead of a quarter-wave plate, optimized at 457 nm, we employed a half-wave plate optimized at 633 nm. The required elliptic state at the input of the TNLCD was generated by the appropriate arrangement of the linear polarizer and the wave plate.

The symmetry concerning the fabric pattern is not always suitable for the quality that we expected from fabric textile. The moire effects produced by a periodic structure may be caused by various and diverse factors as folds, lines, etc. The defect that we are concern is bright and dark fringes appearing in the Nylon Fabric are viewed with necked eye, from a particular angle using white light. To prevent these annoying effects, one should be focusing the research basically on geometrical fabric structure, physical, optical and dyeing.
We start this work by an exhaustive study made to obtain enough information in order to identify and analyze the problem in order to identify, explain and prevent it appearance. To realize that we may define the factors that causes the phenomena. Concerning the experimental results, we begin with a conventional experiment called "Flat table examination" using Fluorescent white light bulb as types of illumination. We have used as well a microscope examination. It is useful to inspect the fiber and yarns which may have different characteristics of size and form. The light interaction with the fiber will produce especially kind of reflection and absorption.
We finish the work by designing and developing an optical system able not only for detecting those kinds of fringes. As well to allow some defects inspection. We believe that some measurements are necessary during some process of fabrication (dyeing, spinning and knitting), at least to reduce this types of defects.

In this work we propose a generalization of the convolution kernel capable of realizing image processing operations as edge enhancement, phase visualization, image restoration, by using a joint transform correlator. The proposal convolution kernel is designed according to the operation to be performed. We present numerical simulations for each convolution kernel which performs the corresponding operation. On the other hand, experimental results are presented from the optical implementation of the convolution kernel by using a joint transform correlator which has the advantage of avoiding alignment difficulties presented by classical Fourier processors.

Systems for automatic pattern recognition can be performed by Artificial Neural Networks and Optical Correlators. Here, we present the design and implementation of a scheme which takes the advantages of both systems to develop an hybrid opto-digital processor, with applications in character recognition. The implementation of this system is based in the Hopfield inner products model using a Joint Transform Correlator. The procedure of recognition has the following steps: since a correlation peak is proportional to the inner product, the Hopfield method computes the inner product of the input and each memory using the Hybrid Opto-Digital Joint Transform Correlator. The second step performs a multiplication between the inner product and its respective memory, all this scaled images are added to get the future state of the input. The associative memory is replaced by two images with information of all images in the memory, this memories are added in the last step. The signal output is threshold and feedback as an input for the next iteration. The process stops when the output image does not change in the next iteration. The final image corresponds to the closest image in the memory of the signal input. This implementation is strong and has low cost, with potential applications for real time pattern recognition.

We present the design of an hybrid opto-digital joint transform correlator using a Fourier optical processor in combination of an electronic system based in a digital signal processor (DSP) or a field programmable gate arrays (FPGA).

We present a new concept for 3D shape recovery using Defocused Structure Light (DSL) images. DSL technique externally extracts the depth information for the scene by using projections of cylindrical wavefronts on the object. These projections show different degrees of defocus as a function of the depth.

In this work the Guided Beam Deflection Method is introduced as a potential tool to design a variety of low-cost IO sensors. A theoretical analysis of the propagation and deflection of confined Gaussian beams in slab waveguides is given. The proposed method is compared to interferometric techniques in terms of sensitivity. It is found that both techniques have sensitivities of the same order of magnitude, however, IO beam deflection sensors may be less expensive than interferometric ones.

We present Talbot array illuminators based on multilevel phase gratings that exhibit two bright zones for period. Our scheme is based in a matrix description for Fresnel diffraction of substructured gratings that allows us to foresee structural relationships between the diffractive element and its Fresnel wavefield.

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